New euthycarcinoids and an enigmatic arthropod from the British Coal Measures

Abstract

Two new species of euthycarcinoids (Arthropoda), Kottixerxes anglicus sp. nov. and Smithixerxes pustulosus sp. nov., are described from the Coal Measures of Westhoughton, Lancashire and Coseley, West Midlands (Westphalian A and B respectively). Both genera are previously known from Mazon Creek, USA (Westphalian D). An additional, enigmatic arthropod with possible euthycarcinoid affinities, Arthrogyrinus platyurus gen. et sp. nov., is described from Coseley. Hypotheses concerning the phylogenetic position of euthycarcinoids are critically reviewed.